Significant technical and clinical innovations in CV CT continue to appear at a rapid pace, despite the struggling economy and continued pressure to reduce spending for medical imaging. Robust attendance at the July scientific meeting of the Society of Cardiovascular Computed Tomography in Denver suggested that enthusiasm was high for reports of new methods that reduce radiation dose and improve the diagnostic yield of cardiac CT.

Good payer news included an announcement from the Blue Cross Blue Shield (BCBS) Medical Advisory Panel, which concluded that patients with acute chest pain presenting the ED with low risk for acute coronary syndrome meet the BCBS Technology Evaluation Center’s criteria for CT angiography. This June 30, 2011, opinion clears the way for individual BCBS member companies to join many other payers in covering the use of cardiac CT for appropriate patients presenting the ED with chest pain.

Several presentations at the meeting addressed increasingly effective methods for reducing the amount of radiation delivered to patients during CV CT imaging. Using advances in detector design and image acquisition techniques, coupled with dramatically improved reconstruction algorithms employing intense digital processing for iterative reconstruction, General Electric, Philips, Siemens and Toshiba all now make systems that produce high-quality CT coronary angiograms using less than 1 mSv radiation — an almost inconsequential dose. Many of these protocols also use much lower volumes of iodinated contrast than traditional protocols, reducing both the expense and the risk for renal toxicity associated with cardiac CT. These new ultra-low radiation protocols may make CT perfusion imaging a clinical reality, as addressed in numerous scientific presentations at the meeting. Ricardo Cury, MD, of Baptist Hospital in Miami, is leading a large multicenter trial of CT myocardial perfusion. Constantly improving image quality also led to encouraging results from several investigators using CT to characterize the structure and quantity of atherosclerotic plaque.

Perhaps the most revolutionary new development at the meeting was a report by James Min, MD, of Cedars-Sinai Los Angeles and current president of the Society of Cardiovascular Computed Tomography, which compared calculation of fractional flow reserve (FFR) from standard CT coronary angiograms to FFR measured using an intracoronary pressure wire in the cardiac cath lab. Charles Taylor, PhD, formerly at Stanford University, has developed fluid dynamic models of the coronary circulation that can be processed using a supercomputer to produce FFR data strikingly similar to those measured in the cath lab. Min reported results of a recently completed multicenter feasibility trial comparing noninvasive CT-FFR measurements to invasive FFR. Further research is now under way to determine just how robust this method will be in routine clinical practice. Numerous recent trials have emphasized the need to assess the functional impact of coronary stenosis, not just visualization of the percent of luminal narrowing. Reliable and convenient assessment of FFR using standard coronary CT angiograms could revolutionize imaging in CHD, providing simultaneous assessment of anatomy and function, with significant reduction in the need for layered testing using stress nuclear, echo and CV MRI, as well as reducing the need for diagnostic catheter coronary angiography. FFR-CT could be a game-changer in this cost-conscious, evidence-demanding environment.

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The link between dietary salt intake and risk for CVD has become an exceedingly contentious issue. The defensive/aggressive authoritarianism commonly exuded over recommendations regarding salt intake in hypertension seems more suited to medieval theologians than to contemporary scientists. This is perhaps not surprising in view of the fact that a comprehensive Medline search from 1966 to the present using the terms “high blood pressure,” “hypertension,” “salt” and “sodium” revealed more than 10,000 articles dealing with these topics. As the reader may remember, the link between dietary salt and high BP was raised more than 100 years ago by Ambard and Beaujard. The Medline search covers, therefore, only one-third of the time during which this link has been researched and discussed.

Given such a plethora of information, a thorough, comprehensive, yet objective, analysis of the literature pertaining to salt and hypertension is most likely beyond the intellectual capacity of even the most skilled scientists. Information overload engenders helplessness and frustration, and the most common defensive mechanism consists in selective reading of the literature (cherry-picking). Thus, the reaction in view of this scientific fog covers the whole spectrum, from apathy on one side, to fervent evangelism on the other. Because most dietary salt intake originates from processed food, the world’s major food manufacturers are interested in keeping the controversy alive. It is then of little surprise that pecuniary interests have taken the salt debate far beyond a purely scientific level.

Debate over population-wide benefit

In a position paper of the American Society of Hypertension, Appel and colleagues concluded: “In view of the age-related rise in BP in both children and adults, the direct, progressive relationship of BP with CV-renal disease throughout the usual range of BP, and the worldwide epidemic of BP-related disease, efforts to reduce BP in non-hypertensive as well as hypertensive individuals are warranted.” A variety of national and international guidelines for the treatment of CVD take a similar viewpoint. Thus, there seems to be consensus that population-wide reduction in salt intake could possibly translate into an impressive reduction in CV morbidity and mortality.

Indeed, a recent study in The New England Journal of Medicine has estimated that a national effort to reduce daily salt intake by 3 g could reduce the annual number of strokes by 32,000, to 66,000; MI by 54,000, to 99,000; and reduce the annual number of deaths from any cause by 44,000, to 92,000. This intervention could also save $10 billion to $24 billion in health care costs annually. However, a study in the May issue of JAMA has rekindled controversy. Stolarz-Skrzypek found that systolic BP correlated positively with 24-hour urinary sodium excretion (similar to what has been reported in previous studies). In contrast to most previous studies, lower sodium excretion predicted higher CV mortality. The authors stated that their findings did “not support the current recommendations of the generalized and indiscriminate reduction of salt intake at the population level.”

Not surprisingly, these findings stirred the leaves in the teapot, and in view of the 50% higher mortality that was found in the lowest tertile of sodium excretion in the Stolarz-Skrzypek study, news media reported that sodium reduction was ineffective and useless. As to the possible pathophysiologic mechanism accounting for the increase in CV morbidity and mortality, the authors speculated that salt intake low enough to decrease BP was prone to stimulate sympathetic activity, to decrease insulin sensitivity, to activate the renin angiotensin system and also to stimulate aldosterone release from the adrenal cortex.

When salt is detrimental

The paper by Stolarz-Skrzypek was extensively criticized by several scientists. The most pertinent criticisms were perhaps that salt intake as estimated by just one calculation of urinary sodium excretion at the start would hardly reflect salt intake during several years of the study. The inherent paradox of the study, that BP increased with salt intake but that morbidity and mortality fell with salt intake, was impossible to explain. Incomplete and unreliable 24-hour urine collections may have hampered the study. The Lancet commented that “this study is disappointingly weak and constitutes little to our understanding of salt and disease. It is likely to confuse public perceptions of the importance of salt as a risk factor for high BP, heart disease and stroke.”

Perhaps the exact relationship between sodium intake and BP is difficult to establish, but we should remember that a high salt intake also has been shown to cause target organ disease independent of BP. In the INTERSALT study, median 24-hour urinary sodium excretion strongly correlated with stroke mortality. Experimental studies have shown that rates of stroke and death are higher on a high salt intake than on a low salt intake, despite similar BP levels. High salt intake has also been related to hypertensive heart disease. Independent of BP, dietary salt is a determinant of left ventricular hypertrophy. Similarly, a link between hypertensive renal disease and salt intake has been established. A high salt intake in salt-sensitive patients seems to accentuate the risk for proteinuria and glomerular injury. Thus, there is solid evidence that a high salt intake may not only raise BP but have a BP independent detrimental effect on heart, kidneys and brain.

Take-home message for the physician

Ever since the lively debates of Sir George Pickering and Lewis Dahl, scientists have continued to waste ink on the relationship between dietary salt intake and BP. In doing so, most of them were oblivious to the possibility that dietary salt may exert direct harmful effects on the CV system independent of arterial pressure. Given the uncertainty and the quasi-religious fervor of proponents and opponents alike, what then should be the take-home message, if any, for the practicing physician? Is salt a powerful poison and, as such, the culprit of a major plague of humankind, causing millions of heart attacks and strokes every year, or, indeed, is it Mother Nature’s own best inhibitor of the renin-angiotensin system?

As with other issues, physicians should attempt to weigh the general evidence against the particular needs of the individual patient. The general evidence suggests that a reduction of dietary salt intake may have some CV benefits that extend beyond those (if any) conferred by the small decrease in BP. Self-monitoring of BP will allow patients to appreciate the effects of a low-salt diet. A modest salt reduction interferes little, if at all, with the needs of the individual and therefore should be recommended as a simple measure for the prevention of CVD, certainly in hypertensive patients and their offspring, but possibly in normotensive patients as well.

Ambard L. Arch Gen Med. 1904;193:520-533.

Appel L. J Clin Hypertens (Greenwich). 2009;11:358-368.

Bibbins-Domingo K. N Engl J Med. 2010;362:590-599.

Stolarz-Skrzypek K. JAMA. 2011;305:1777-1785.

Salt and cardiovascular disease mortality. Lancet. 2011;377:1626.

Disclosure: Dr. Messerli reports no relevant financial disclosures.

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Debate over the federal budget continues to rage in Washington, D.C., and with little consensus other than vacillating recognition that the government’s expenditures continue to grow faster than its revenues and at an unsustainable rate.

In recommending either a $6 trillion cut (proposed by US Rep. Paul Ryan of Wisconsin) or a $4.3 trillion cut (President Obama’s proposal), both parties acknowledge that steadily increased spending for Medicare and Social Security cannot continue. Political reality suggests any changes in these popular programs will be incremental, cautious and as inoffensive as possible to voters — especially seniors. Fundamental ideological differences persist, credible court cases are pending, continued calls to repeal recent health care legislation are still being issued, and the presidential election is 18 months away.

Consensus underlying the contentious rhetoric suggests that cardiologists and other physicians will share in the pain of anticipated reduction in federal spending for health care, regardless of how these partisan issues are eventually resolved.

The advent of ACOs

As pressure mounts to control costs, various methods for motivating physicians and health care systems to provide high-quality care while compensating them less are evolving. The CMS, which controls Medicare and often sets the stage for private health insurers, recently released its proposed rules for creating accountable care organizations (ACO), which are the centerpiece of the Patient Protection and Accountable Care Act for restructuring Medicare. As an alternative to paying prespecified fees to individual physicians and hospitals for providing individual services to each Medicare patient cared for, CMS would pay a variable amount for an episode of care, including primary as well as specialty physician and hospital services.

An ACO would need to have at least 5,000 Medicare beneficiaries to be eligible to participate and demonstrate “meaningful use” of an electronic medical record, so that a minimum level of quality of care can be demonstrated as costs are reduced. These quality measures would change over time and would include patient experience, care coordination, patient safety, preventive services and assessment of the at-risk population served. Patients would be attributed to the ACO based on CMS retrospective review of billing records to determine where the plurality of their care was delivered. Bonus payments could be made to ACOs if spending for care of its member patients is less than anticipated based on a complex benchmarking formula.

These bonus payments would presumably be distributed among the primary and specialty physicians delivering care through some sort of sharing mechanism, not based explicitly on limiting services to patients. How these payment mechanisms would actually work in practice is not yet defined, but the process for implementing an alternative to the fee-for-service system is well under way, despite the continued partisan rhetoric in Washington.

Changes in physician compensation likely

Private insurers have more flexibility but often follow CMS’ lead in determining payment structure. Pre-authorization for imaging services to reduce utilization is an example of cost control widely employed in the private sector to control expenses. WellPoint Blue Cross, one of the nation’s largest health insurers, recently announced it will no longer automatically grant routine annual payment increases to hospitals, but will base rate increases on WellPoint’s assessment of “treatment quality,” with a formula based on health outcomes, patient safety measures and patient satisfaction.

Hospitals, long accustomed to receiving automatic rate increases, can be expected to respond to measures such as these by documenting compliance with measured performance and by reducing costs, including reducing payment to their employed physicians. Hospitals have never made money directly by hiring physicians, but they intend to profit by controlling referrals for lucrative inpatient services. Employed physician salaries will track downward as these inpatient services become less lucrative.

Even if the Patient Protection and Accountable Care Act is repealed or replaced by some sort of defined benefit voucher plan directing Medicare recipients to shop for their own care, it seems likely that systems will evolve to replace open-ended fee-for-service reimbursement for physician services. Small groups and solo practitioners may be able to form “virtual” ACOs, but comprehensive integrated health care systems seem to have an advantage in forming ACOs, particularly for a specialty such as cardiology. Both Republican and Democratic proposals rely on tax credits to purchase private insurance, with managed competition through state-based exchanges, cost-sharing for most patients and ever stricter external controls on Medicare cost growth. None of these factors favor independent practice or translate to more money for cardiologists.

The challenges of collaboration

The American College of Cardiology and others are calling on physicians to meet these challenges with innovative new ideas for collaboration between health care executives and integration of appropriately trained physician leaders into the management structure of hospitals and health care organizations to eliminate waste and inefficiency while improving access to and delivery of appropriate health care services in a cost-effective and patient-oriented environment.

This is a formidable task. Faced with continued, severe reductions in their income and loss of autonomy, many cardiologists are skeptical, frightened, angry or, at best, reluctantly resigned to working in systems that give more control and higher salaries to mid-level non-physician managers than to physicians involved in direct patient care.

It seems likely that most of us will move away from being paid for each service we perform (piecework) and migrate to a system in which we are salaried to perform our duties in a regulated environment that emphasizes not just how much we do, but how effective and valuable our actions are. The devil is in the details as to how effectiveness and value are defined, monitored and rewarded.

There simply are no easy solutions to these problems. We all should hope that success will come to those who focus on patients and their individual and collective well-being; that responsible members of our profession and society will collaborate to deliver cost humane and effective health care to all.

As you read these remarks, I hope you will respond to this entry with your own thoughts and ideas on how to meet these challenges:

• If you intend to avoid hospital employment, how will you meet the financial and operational challenges ahead?
• If you are employed or contemplating it, what advice can you share on how to preserve the best of past practices while adapting to the new order?
• Will you try to avoid some of these issues by restricting your practice to those who can and will pay for service like you have always given?
• Are you “burned out” and weary of all this noise? Will you retire or just become a disgruntled salary man?
• What would you say to a friend’s daughter or son who is applying to medical school or for cardiology fellowships?

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